Sketching with Pen: Good or Bad

So I have run into snags sometimes with grabbing a 2B and have simply resorted to ball-point pens for now. I was told to never erase for quick sketches anyway so I figured this isn't an issue, but is it? I have been working on line quality and confident line-work and practice IS practice, so I have seen improvements but am I hindering some potential through use of only ink? Thank you for your time.

I don't think using a pen will hinder your quality. For me, using a pen is infinitely easier and produces higher quality sketches. Although I think ballpoint pens aren't amazing for sketches, - try pilot pens or the like, they enable a flow of ink without the need of pressing on the paper. This is also why I prefer pens to pencils, for example. Also, the fact that I don't have the possibility to erase helps me move forward and make more sketches, regardless of small mistakes that I can't help but erase when using a pencil.
I hope this helped, this is just from my personal experience.

Thank you for the advice on the pilot pens. I tried them and have more fun with sketching! I have been using pens for my practice and haven't had too much issue and tried to switch back to pencil for comparison-sake and do the same thing with eraser sickness. Thank you for the advice and I look forward to more use of this site.

Ball point pens are now one of my favorite tools. Just the ordinary cheap papermate fine point. The lines are very black so scanning them in is really easy. Also the ink drys fast so you don't get smudge marks while your working fast. A soft pencil quality can be achieved with a very light touch and later you can get very dark hard lines also.

When working on gesture practice, I now use an ink pen. Currently a "Faber-Castell Broadpen 1554 0.8 mm", but I'm sure it'll dry up soon, and I'll be out looking for something similar in the shops here.

I gave up using pencils for these quick gestures, as I caught myself making too many lines and not commiting myself enough to my lines.

If I draw a line now, and it is "wrong", I just leave it. It is part of the process to see the obvious mistakes I made during the sketch. I'm not looking for publishable results, I'm on a very shallow but permanent learning curve. Reflecting on my mistakes is just as important as drawing gestures on a regular basis.

Is good for me i train that way
and now, how do I make a topic?

Use whatever you want man. I use a ballpoint a lot too and holding it it more comfortable then most pencils that I've used. Plus since you can't erase, you're forced to think about your lines before you put 'em down. Once its there, you'd better move on, whether the line is good or not. So use them. Sometimes its easier than using a pencil.